The case against the "gay gene"

What "Born This Way" got wrong, and whether we should even search for a genetic cause for sexuality

Marchers at a gay rights rally holding a sign that says "Equality Without Exemptions"
Photo by Nikolas Gannon / Unsplash

The search for the “gay gene,” or any other biological explanation for same-sex attraction or sexual activity is an old endeavor. Some researchers have tried predicting sexual orientation with digit ratios— the ratio of the lengths of different fingers. Others have looked at birth order, suggesting that younger male siblings might be more likely to be queer.

A blockbuster study, published in Science in 2019 by geneticist Andrea Ganna and colleagues from around the world, reported something more precise. They reported that though there was not one single “gay gene” that caused queerness, there was still a genetic architecture underlying same-sex attraction. It was such a big hit the New York Times covered it.

Earlier this year, an interdisciplinary team of biologists criticized Ganna’s conclusions in their own review of sex and sexuality research. These researchers, from Harvard’s GenderSci Lab, describe what they call “The New Genetics of Sexuality.” Their review explores the history of research into genetics, and the ramifications of protecting the rights of queer people using “Born This Way” rhetoric. I recently spoke with two of the paper’s authors over Zoom, graduate student Alex Borsa and postdoc Mia Miyagi, about what genetics can say about human behavior and the unintended consequences of well-meaning activism. 

The New Genetics of Sexuality | GLQ | Duke University Press

This interview has been edited for clarity.

What was research around sexual behavior like in the pre-genomics era?

Mia Miyagi: Before modern genetic data, people were interested in the idea of a gay gene, as a theoretical construct without data, though there were actual studies looking for genetic components to queerness. 

There were other hypotheses like that XYY individuals were hyper masculine, hyper violent, so on and so forth. And there were studies of people in prisons, looking at their karyotype [Ed: a study of the physical appearance of a person’s chromosomes] and trying to find some biological reason for for their incarceration. It later turned out to all be bunk. But this was real work, this was not done by crackpots. This was real science, looking for a genetic reason for a really socially complicated thing.

Alex Borsa: Evolutionary psychology has its roots in eugenics over the course of the late 19th and early 20th centuries. We see its echoes operating now under slightly different, supposedly more advanced, supposedly more ethical, supposedly more rigorous and scientific types of research programs. Kathryn Paige Harden published a book essentially saying that in order to fix educational justice and disparities, we need to know everyone's genomes. These are wild socio-political visions. And Jordan Peterson, right? There are ideas like “we found this one random detail on some random species, and that means that hierarchies are good for humans and men dominate women and testosterone is the key to life.” Truly batshit things. It’s pretty much non-falsifiable, haphazard, and spurious hypotheses that are transcendental across all times and places for all human populations, from very particular and contextual data subsets. But that’s mostly my opinion on the matter.